Many people worldwide are affected by inflammatory diseases or disorders such as gout, acute or chronic idiopathic inflammatory arthritis, psoriasis, chronic dermatosis, myositis, demyelinating diseases, chronic obstructive pulmonary disease (COPD), interstitial lung disease, glomerulonephritis, interstitial nephritis, chronic active hepatitis, Crohn's disease, ulcerative colitis, plaque formation in atherosclerosis, degenerative diseases of the joints or nervous system, or multiple sclerosis (MS). Globally, populations are ageing and an increasing number of people require medication for age-related inflammatory diseases such as arthritis and gout. Similarly, there is an increase in the prevalence of allergic diseases such as asthma.
Steroids are one treatment option for inflammatory disorders such as asthma and arthritis. However, long term use of steroids gives rise to chronic side effects, including immunosuppression, tissue wasting and loss of bone density.
Another well-known class of anti-inflammatory pharmaceuticals is the non-steroidal anti-inflammatory drugs (NSAIDs). The primary mode of action of known NSAIDs is through inhibition of the COX enzyme, which results in the inhibition of prostaglandin synthesis. There are two different isoforms of the COX enzyme, COX-1 and COX-2. NSAIDs inhibit both isoforms to varying degrees.
The NSAIDs currently in the marketplace provide some alternative to steroid-based treatments. However, administration of NSAIDs can cause highly undesirable side effects such as gastro-intestinal bleeding, ulcers and renal disease. In certain cases, these drugs do not provide effective relief for some sufferers of inflammatory disease.
Thus, there is currently a need for new anti-inflammatory pharmaceuticals with reduced side effects.
As part of their search for new NSAIDs, the applicants have targeted a different part of the inflammatory cascade, seeking compounds that inhibit superoxide release by neutrophils and/or suppress neutrophil infiltration. This search has focussed on natural products as lead compounds.
The vast diversity of natural flora and fauna provides a large and varied source of natural product compounds with interesting structures and biological activities. Marine organisms, for example, can be a rich source of compounds, some of which possess surprising and useful activities.
Recently, interesting quinones have been isolated from ascidians. Compounds (A) and (B) were isolated from the Mediterranean ascidian Aplidium conicum (A. Aiello et al., Eur. J. Org. Chem., 2003, 898).

These compounds are of interest for their potential anti-cancer properties, and were found to be cytotoxic to rat glioma cells in vitro. However, they are not known to possess anti-inflammatory activity.
Synthetic quinoline-quinones are also known. Townsend and Jackson reported the synthesis of compound (C) in four steps from N-(4-bromo-2,5-dimethoxyphenyl)acetamide (N. O. Townsend and Y. A. Jackson, Org. Biomol Chem., 2003, 1, 3557).

The compound was not reported to have any biological activity.
U.S. Pat. No. 3,040,041 discloses the synthesis of compounds (D), (E) and (F), which are tuberculostatic agents.

The synthesis of compound (G) from hypotaurine and naphthoquinone has been reported (F. J. Schmitz and S. J. Bloor, J. Org. Chem., 1988, 53, 3922). The data reported by Schmitz and Bloor for the product isolated from the reaction of hypotaurine and naphthoquinone actually correspond to the quinone (H), but the structure was incorrectly reported as compound (G).

The isolated product (i.e. compound (H)) was found to be cytotoxic to lymphocytic leukemia cells in vitro.
Schelihammer et al. have reported the synthesis of compound (J) (C. W. Schellhammer and S. Petersen, Ann. (1959) 624, 108-119). This compound was found to have chemotherapeutic activity, but was not reported to have any anti-inflammatory activity.

The applicants' research has led to the isolation of novel anti-inflammatory compounds from ascidians, in particular from an unnamed species (Aplidium sp. 15 ascidian). These compounds have provided a lead into the new class of anti-inflammatory compounds that is the subject of this application. The natural products and their synthetic derivatives and analogs form the basis of a new class of NSAIDs, with a different mode of action from known NSAIDs.
It is therefore an object of the invention to provide a novel class of anti-inflammatory compounds, or at least to provide a useful choice.